Azeotrope-like compositions of pentafluoropropane, hydrocarbons and water

ABSTRACT

This invention provides compositions of 1,1,1,3,3-pentafluoropropane, water and at least one hydrocarbon selected from the group consisting of n-pentane, isopentane, cyclopentane and hexane that are environmentally desirable for use as refrigerants, aerosol propellants, metered dose inhalers, blowing agents for polymer foam, heat transfer media, and gaseous dielectrics.

This application is a division of application Ser. No. 09/267,999 filedMar. 15, 1999, now U.S. Pat. No. 6,100,230.

FIELD OF THE INVENTION

The present invention relates to azeotrope-like mixtures of1,1,1,3,3-pentafluoropropane (“HFC-245fa”), water (“H₂O”) and at leastone hydrocarbon. The compositions of the invention are environmentallydesirable for use as refrigerants, in centrifugal chillers, aerosolpropellants, metered dose inhalers, fire extinguishers, blowing agentsfor polymer foam, heat transfer media, solvents, and gaseousdielectrics.

BACKGROUND OF THE INVENTION

Fluorocarbon based fluids have found widespread use in industry in anumber of applications, including as refrigerants, aerosol propellants,blowing agents, heat transfer media, and gaseous dielectrics. Because ofthe suspected environmental problems associated with the use of some ofthese fluids, it is desirable to use fluids of no ozone depletionpotential such as hydrofluorocarbons, (“HFC's”).

Thus, the use of fluids that do not contain chlorofluorocarbons(“CFC's”) or hydrochlorofluorocarbons (“HCFC's” is desirable).Additionally, it is known that the use of single component fluids orazeotropic mixtures, which mixtures do not fractionate on boiling andevaporation, is desirable. However, the identification of new,environmentally safe, azeotropic mixtures is complicated due to the factthat it is difficult to predict azeotrope formation.

The art continually is seeking new fluorocarbon based mixtures thatoffer alternatives, and are considered environmentally safer substitutesfor CFC's and HCFC's. Of particular interest are mixtures containing afluorocarbon and a non-fluorocarbon, both low ozone depletionpotentials. Such mixtures are the subject of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plot of foam k-factor versus the amount of HFC-245fa in theblowing agent blend at three different temperatures.

DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

This invention provides azeotrope-like compositions of HFC-245fa, waterand at least one hydrocarbon selected from the group consisting ofn-pentane, isopentane, cyclopentane and hexane (C₅-C₆ hydrocarbons). Thecompositions of the invention provide environmentally desirable, zeroozone depletion potential replacements for currently used CFC's andHCFC's. Additionally, the compositions of the invention exhibitcharacteristics that make the compositions better CFC and HCFCsubstitutes than any of HFC-245fa, C₅-C₆ hydrocarbons or water alone.

One embodiment of the invention provides azeotrope-like compositionscomprising HFC-245fa, water and at least one hydrocarbon selected fromthe group consisting of n-pentane, isopentane, cyclopentane and hexane.More specifically, the invention provides azeotrope-like compositionscomprising from about 65 to about 98 weight percent HFC-245fa, fromabout 34 to about 1 weight percent of at least one hydrocarbon selectedfrom the group consisting of n-pentane, isopentane, cyclopentane andhexane, and from about 34 to about 1 weight percent water, whichcompositions have a boiling point of 10° C.±4 preferably±1° C., at 760mm Hg pressure. The preferred, more preferred, and most preferredcompositions of the invention are set forth in Table 1. The numericalranges in Table 1 are to be understood to be prefaced by the term“about”.

TABLE 1 Preferred More Preferred Most Preferred Components (wt %) (wt %)(wt %) HFC-245fa 65-98 75-98 85-98 C₅—C₆ Hydrocarbons 34-1 24-1 15-1Water 34-1 24-2 15-3

The invention relates to a method of preparing polyurethane andpolyisocyanurate foam compositions comprising the step of reacting andfoaming a mixture of ingredients which react to form polyurethane orpolyisocyanurate foams in the presence of a blowing agent comprising anazeotrope-like composition consisting essentially of preferably fromabout 65 to about 98 weight percent, more preferably from about 75 toabout 98, most preferably form about 85 to about 98 weight percentHFC-245fa; from about 34 to about 1, more preferably from about 24 toabout 1, most preferably from about 15 to about 1 weight percent of atleast one hydrocarbon selected from the group consisting of n-pentane,isopentane, cyclopentane and hexane; and preferably from about 34 toabout 1, more preferably from about 15 to about 2, most preferably fromabout 15 to about 3 weight percent water.

The invention further relates to a closed cell foam prepared from apolymer foam formulation containing a blowing agent comprising anazeotrope-like composition consisting essentially of preferably fromabout 65 to about 98 weight percent, more preferably from about 75 toabout 98, most preferably form about 85 to about 98 weight percentHFC-245fa; from about 34 to about 1, more preferably from about 24 toabout 1, most preferably from about 15 to about 1 weight percent of atleast one hydrocarbon selected from the group consisting of n-pentane,isopentane, cyclopentane and hexane; and preferably from about 34 toabout 1, more preferably from about 15 to about 2, most preferably fromabout 15 to about 3 weight percent water.

In another embodiment, the invention provides a closed cell foamcontaining a cell gas comprising a blowing agent comprising anazeotrope-like composition consisting essentially of preferably fromabout 65 to about 98 weight percent, more preferably from about 75 toabout 98, most preferably form about 85 to about 98 weight percentHFC-245fa; from about 34 to about 1, more preferably from about 24 toabout 1, most preferably from about 15 to about 1 weight percent of atleast one hydrocarbon selected from the group consisting of n-pentane,isopentane, cyclopentane and hexane; and preferably from about 34 toabout 1, more preferably from about 15 to about 2, most preferably fromabout 15 to about 3 weight percent water.

The invention further relates to a blowing agent composition comprisingan azeotrope-like composition consisting essentially of preferably fromabout 65 to about 98 weight percent, more preferably from about 75 toabout 98, most preferably form about 85 to about 98 weight percentHFC-245fa; from about 34 to about 1, more preferably from about 24 toabout 1, most preferably from about 15 to about 1 weight percent of atleast one hydrocarbon selected from the group consisting of n-pentane,isopentane, cyclopentane and hexane; and preferably from about 34 toabout 1, more preferably from about 15 to about 2, most preferably fromabout 15 to about 3 weight percent water.

For purposes of this invention, azeotrope-like compositions arecompositions that behave like azeotropic mixtures. From fundamentalprinciples, the thermodynamic state of a fluid is defined by pressure,temperature, liquid composition, and vapor composition. An azeotropicmixture is a system of two or more components in which the liquidcomposition and vapor composition are equal at the state pressure andtemperature. In practice, this means that the components of anazeotropic mixture are constant boiling and cannot be separated during aphase change.

Azeotrope-like compositions behave like azeotropic mixtures, i.e., areconstant boiling or essentially constant boiling. In other words, forazeotrope-like compositions, the composition of the vapor formed duringboiling or evaporation is identical, or substantially identical, to theoriginal liquid composition. Thus, with boiling or evaporating theliquid composition changes, if at all, only to a minimal or negligibleextent. This is to be contrasted with non-azeotrope-like compositions inwhich, during boiling or evaporation, the liquid composition changes toa substantial degree. All azeotrope-like compositions of the inventionwithin the indicated ranges as well as certain compositions outsidethese ranges are azeotrope-like.

The azeotrope-like compositions of the invention may include additionalcomponents that do not form new azeotropic or azeotrope-like systems, oradditional components that are not in the first distillation cut. Thefirst distillation cut is the first cut taken after the distillationcolumn displays steady state operation under total reflux conditions.One way to determine whether the addition of a component forms a newazeotropic or azeotrope-like system so as to be outside of thisinvention is to distill a sample of the composition with the componentunder conditions that would be expected to separate a nonazeotropicmixture into its separate components. If the mixture containing theadditional component is nonazeotropic or nonazeotrope-like, theadditional component will fractionate from the azeotropic orazeotrope-like components. If the mixture is azeotrope-like, some finiteamount of a first distillation cut will be obtained that contains all ofthe mixture components that is constant boiling or behaves as a singlesubstance.

It follows from this that another characteristic of azeotrope-likecompositions is that there is a range of compositions containing thesame components in varying proportions that are azeotrope-like orconstant boiling. All such compositions are intended to be covered bythe terms “azeotrope-like” and “constant boiling”. As an example, it iswell known that at differing pressures, the composition of a givenazeotrope will vary at least slightly, as does the boiling point of thecomposition. Thus, an azeotrope of A and B represents a unique type ofrelationship, but with a variable composition depending on temperatureand/or pressure. It follows that, for azeotrope-like compositions, thereis a range of compositions containing the same components in varyingproportions that are azeotrope-like. All such compositions are intendedto be covered by the term azeotrope-like as used herein.

The compositions of the invention meet the need in the art for HFCmixtures that have no ozone depletion potential and are negligiblecontributors to greenhouse global warming. Further, because theazeotrope-like compositions of the invention exhibit constant vaporpressure characteristics and relatively minor composition shifts as theliquid mixture is evaporated, the azeotrope-like composition of theinvention are comparable to a constant boiling single componentcomposition.

In another process embodiment, the compositions of the invention areused in a method for producing polyurethane and polyisocyanurate foams.Any of the methods well known in the art such as those described in“Polyurethanes Chemistry and Technology,” Volumes I and II, Saunders andFrisch, 1962, John Wiley and Sons, New York, N.Y. In general, the methodcomprises preparing polyurethane or polyisocyanurate foams by combiningan isocyanate, a polyol or mixture of polyols, a blowing agent ormixture of blowing agents, and other materials such as catalysts,surfactants, and optionally, flame retardants, colorants, or otheradditives. The blowing agent or agents employed shall be a volatilemixture of the azeotrope-like compositions of the present invention.

It is convenient in many applications to provide the components forpolyurethane or polyisocyanurate foams in preblended formulations. Mosttypically, the foam formulation is preblended into two components. Theisocyanate and optionally certain surfactants and blowing agentscomprise the first component, commonly referred to as the “A” component.The polyol or polyol mixture, surfactant, catalysts, blowing agents,flame retardant, and other isocyanate reactive components comprise thesecond component, commonly referred to as the “B” component.Accordingly, polyurethane or polyisocyanurate foams are readily preparedby bringing together the A and B side components either by hand mix forsmall preparations and, preferably, machine mix techniques to formblocks, slabs, laminates, pour-in-place panels and other items, sprayapplied foams, froths, and the like. Optionally, other ingredients suchas fire retardants, colorant auxiliary blowing agents, and even otherpolyols can be added as a third stream to the mix head or reaction site.Most conveniently, however, they are all incorporated into one Bcomponent as described above.

It is also possible to produce thermoplastic foams using thecompositions of the invention. For example, conventional foampolyurethanes and isocyanurate formulations may be combined with theazeotrope-like compositions in a conventional manner to produce rigidfoams.

Azeotrope-like mixtures containing HFC-245fa are particularly suitableas foam blowing agents since foams blown with HFC-245fa have been foundto possess low relative initial and aged thermal conductivity and gooddimensional stability at low temperatures. Of particular interest arethose mixtures that contain HFC-245fa and other zero ozone depletingmaterials, such as, for example, other hydrofluorocarbons, e.g.,difluoromethane (HFC-32), difluoroethane (HFC-152), trifluoroethane(HFC-143), tetrafluoroethane (HFC-134), pentafluoropropane (HFC-245),hexafluoropropane (HFC-236), heptafluoropropane (HFC-227); and inertgases, e.g., air, nitrogen, carbon dioxide. Where isomerism is possiblefor the hydrofluorocarbons mentioned above, the respective isomers maybe used either singly or in the form of a mixture.

Dispersing agents, cell stabilizers, and surfactants may also beincorporated into the blowing agent mixture. Surfactants, better knownas silicone oils, are added to serve as cell stabilizers. Somerepresentative materials are sold under the names of DC-193, B-8404, andL-5340 which are, generally, polysiloxane polyoxyalkylene blockco-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748,2,917,480, and 2,846,458. Other optional additives for the blowing agentmixture may include flame retardants such astris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate,tris(2,3-dibromopropyl)-phosphate, tris(1,3-dichloropropyl)phosphate,diammonium phosphate, various halogenated aromatic compounds, antimonyoxide, aluminum trihydrate, polyvinyl chloride, and the like.

Generally speaking, the amount of blowing agent present in the blendedmixture is dictated by the desired foam densities of the finalpolyurethane or polyisocyanurate foams products. The proportions inparts by weight of the total blowing agent or blowing agent blend canfall within the range of from 1 to about 60 parts of blowing agent per100 parts of polyol. Preferably from about 10 to about 35 parts byweight of HFC-245fa per 100 parts by weight of polyol are used.

In another embodiment, the azeotrope-like compositions of this inventionmay be used as propellants in sprayable compositions, either alone or incombination with known propellants. The sprayable composition comprises,consists essentially of, and consists of a material to be sprayed and apropellant comprising, consisting essentially of, and consisting of theazeotrope-like compositions of the invention. Inert ingredients,solvents, and other materials may also be present in the sprayablemixture. Preferably, the sprayable composition is an aerosol. Suitablematerials to be sprayed include, without limitation, cosmetic materialssuch as deodorants, perfumes, hair sprays, cleansers, and polishingagents as well as medicinal materials such as anti-asthma andanti-halitosis medications.

The components of the composition of the invention are known materialsthat are commercially available or may be prepared by known methods.Preferably, the components are of sufficiently high purity so as toavoid the introduction of adverse influences upon cooling or heatingproperties, constant boiling properties, or blowing agent properties ofthe system. In the case of metered dose inhalers, the relevant currentGood Manufacturing Process may be used for manufacturing thesematerials.

Additional components may be added to tailor the properties of theazeotrope-like compositions of the invention as needed. By way ofexample, oil solubility aids may be added in the case in which thecompositions of the invention are used as refrigerants. Stabilizers andother materials may also be added to enhance the properties of thecompositions of the invention.

The present invention is more fully illustrated by the following,non-limiting examples.

EXAMPLES Example 1

An ebulliometer consisting of vacuum-jacketed tube with a condenser ontop was used. About 20 g HFC-245fa was charged to the ebulliometer, thencyclopentane was added in small, measured increment, and water was addedin small, measured increments. The temperature was measured using aplatinum resistance thermometer. We observed the temperature depressionwhen cyclopentane and water were added to HFC-245fa, which indicates aternary minimum boiling azeotrope is formed. The measurements show thatfrom about 0.1 to about 34 weight percent cyclopentane, and from 0.1 to9 weight percent of water, the boiling point of the composition changedby about 3° C.

Example 2

An ebulliometer consisting of vacuum-jacketed tube with a condenser ontop was used. About 17 g HFC-245fa was charged to the ebulliometer, thenisopentane was added in small, measured increment, and water was addedin small, measured increments. The temperature was measured using aplatinum resistance thermometer. We observed the temperature depressionwhen isopentane and water were added to HFC-245fa, which indicates thata ternary minimum boiling azeotrope is formed. The measurement show thatfrom about 0.1 to about 27 weight percent isopentane, and from 0.1 to 9weight percent of water, the boiling point of the composition changed byabout 7° C. Therefore, the composition is constant-boiling over thisrange.

Example 3

An ebulliometer consisting of vacuum-jacketed tube with a condenser ontop was used. About 12 g HFC-245fa was charged to the ebulliometer, thenhexane was added in small, measured increment, and water was added insmall, measured increments. The temperature was measured using aplatinum resistance thermometer. We observed the temperature depressionwhen hexane and water were added to HFC-245fa, which indicates that aternary minimum boiling azeotrope is formed. The measurement show thatfrom about 0.1 to about 11 weight percent hexane, and from 0.1 to 24weight percent of water, the boiling point of the composition changed byabout 1° C.

Example 4

100 g of a polyether with a hydroxyl value of 380, a result from theaddition of propylene oxide to a solution of saccharose, propyleneglycol and water, is mixed with 2 g of a siloxane polyether copolymer asfoam stabilizer, and 3 g of dimethylcyclohexylamine. With stirring, 100g of the mixture is thoroughly mixed with 15 g of the azeotrope-likecomposition of Example 1 as blowing agent. The resulting mixture isfoamed with 152 g of crude 4,4′ diisocyanatodiphenylmethane. Theresulting rigid foam is inspected and found to be of good quality.

Example 5

In this example, shows that foams prepared using the azeotrope-likecompositions of the invention as a foam blowing agent exhibit improvedk-factors. In general the formulations used to prepare these foams isdescribed in Table 4.

TABLE 4 Component (pbw) Terate 2541¹ 100.00 100.00 100.00 TegostabB8503² 2.00 2.00 2.00 Polycat 8³ 0.4 0.50 0.63 Dabco K-15³ 3.00 3.805.60 Water 0.5 0.5 0.5 HFC-245fa 35.00 17.5 0 Isopentane 0 9.4 18.7Lupranate M70L⁴ 168 168 168 Index 250 250 250 ¹Polyol from COSA;hydroxyl number = 240 ²Surfactant from Goldschmidt Chemical Company³Catalyst from Air Products & Chemicals Inc. ⁴A Polymethylenepoly(phenyl isocyanate) mixture containing about 40% by weight ofmethylenebis(phenyl isocyanate) with the balance being polymethylenepoly(phenyl isocyanate) having a functionality greater than 2;isocyanate equivalent weight = about 134; from BASF Corp.

The same general procedure commonly referred to as “handmixing” was usedto prepare all foams. For each blowing agent or blowing agent pair, apremix of polyol, Terate 2541 surfactant, Tetgostab B8433, and catalyst,Dabco K-15 and Polycat 8, was prepared in the same proportions displayedin Table 4. About 2 kg was blended to insure that all of the foams in agiven series were made with the same master batch of premix. The premixwas blended in a one-gallon pain can, and stirred at about 1500 rpm witha Conn 2″ diameter ITC mixer until a homogenous blend was achieved. Whenmixing was complete the material was transferred to a one-gallon glassbottle and sealed. The bottle was then placed in a refrigeratorcontrolled at 32° F. The foam blowing agents were kept separately in thesame refrigerator, along with the 32 ounce tin cans for mixing vessels.The A-component, isocyanate, was kept in sealed containers at 70° F.

For the individual foam preparations, an amount of B-component equal tothe formulation weight was weighted into a 32-oz tin can preconditionedat 32° F. To this was added the required amounts of the individualblowing agents, also preconditioned to 32° F. The contents were stirredfor two-minutes with a Conn 2″ ITC mixing blade turning at about 1000rpm. Following this, the mixing vessel and contents were reweighed. Ifthere was a weight loss, the lower boiling blowing agent was added tomake up the loss. The contents were stirred for an additional 30seconds, and the can replaced in the refrigerator.

After the contents have cooled again to 32° F., approximately 10minutes, the mixing vessel was removed from the refrigerator and takento the mixing station. A pre-weighed portion of A-component, isocyanate,was added quickly to the B-component, the ingredients mixed for 10second using a Conn 2″ diameter ITC mixing blade at 3000 rpm and pouredinto a 8″×8″×4″ cardboard cake box and allowed to rise. Cream,initiation, gel and tack free times were recorded for the individualpolyurethane foam samples.

The foams were allowed to cure in the boxes at room temperature for atleast 24 hours. After curing, the blocks were trimmed to a uniform sizeand densities measured. Any foams that did not meet the densityspecification 2.0±0.1 lb/ft³ were discarded, and new foams preparedusing an adjusted amount of blowing agent in the formulation to obtainthe specified density.

After ensuring that all the foams meet the density specifications, thefoams were tested for k-factor according to ASTM C518. The k-factorresults are displayed in FIG. 1. This graph illustrates that by usingthe azeotrope-like blends of the invention as the foam blowing agentinstead of only water the k-factors of the foams dramatically improve.The improvement is unexpectedly nonlinear.

In addition to the difference in k-factor, there is a difference in thedensity of the foams produced with these formulations. This isillustrated in Table 5.

TABLE 5 Wt % Blowing Agent vs. Foam Density Wt % HFC-245fa Wt %Isopentane Wt. % Water Foam density (pcf) 98.6 0 1.4 1.91 0 97.4 2.61.87 63.5 34.3 1.8 1.77

This table indicates that the azeotrope-like compositions of theinvention produce foams with significantly lower foam density for thesame molar equivalent of blowing agent.

Example 6

We have found that HFC-245fa aids in solubilizing C₅-C₆ hydrocarbons andblends thereof in the B-component. To demonstrate this effect 0.18 molesof isopentane are added to 50 g of Terate 2541LC¹ in a Fischer portertube. The heights of the layers present in the tube were recorded. Thetest was then repeated with increasing concentrations of HFC-245fa. Thefollowing table summarizes the results of this study.

Improved miscibility of hydrocarbons in B-side with addition ofHFC-245fa Blowing Agent Moles Moles Moles Isopentane 0.18 0.13 0.09HFC-245fa 0 0.05 0.09 % hydrocarbon 29.8 26.3 20.3 layer of polyolblowing agent mixture

Additionally, we have found that the order of addition of the componentsis critical in the optimization of the foam results. HFC-245fa enhancesthe miscibility of the hydrocarbons in the B-component if it is added asa preblended mixture with the hydrocarbon or added to the B-componentprior to addition of the hydrocarbon. The following table illustratesthis phenomenon when 6 grams of each blowing agent is added with aconstant concentration of water to Stepanol 2352.

Improved miscibility of hydrocarbons in B-side with addition ofHFC-245fa

Improved miscibility of hydrocarbons in B-side with addition ofHFC-245fa Blowing Agent Order of addition Isopentane First SecondBlended HFC-245fa Second First Blended % hydrocarbon 62.2 20.4 20.4layer of polyol blowing agent mixture

The improvement in miscibility was unexpected and is believed tocontribute to the inherent stability of the B-component.

What is claimed is:
 1. A method for producing polyurethane andpolyisocyanurate foams comprising reacting and foaming a mixture ofingredients that react to form the polyurethane and polyisocyanuratefoams in the presence of a volatile blowing agent comprising anazeotrope-like composition consisting essentially of1,1,1,3,3-pentafluoropropane, water and at least one hydrocarbonselected from the group consisting of n-pentane, isopentane,cyclopentane and hexane, which compositions have a boiling point of10±4° C. at 760 mm Hg.
 2. The method of claim 1 wherein theazeotrope-like composition consists essentially of from about 65 toabout 98 weight percent 1,1,1,3,3-pentafluoropropane, from about 1 toabout 34 weight percent water and from about 1 to about 34 weightpercent of at least one hydrocarbon selected from the group consistingof n-pentane, isopentane, cyclopentane and hexane.
 3. The method ofclaim 1 wherein the azeotrope-like composition consists essentially offrom about 75 to about 98 weight percent 1,1,1,3,3-pentafluoropropane,from about 2 to about 24 weight percent water and from about 1 to about24 weight percent of at least one hydrocarbon selected from the groupconsisting of n-pentane, isopentane, cyclopentane and hexane.
 4. Amethod for producing polyurethane and polyisocyanurate foams comprisingreacting and foaming a mixture of ingredients that react to form thepolyurethane and polyisocyanurate foams in the presence of a volatileblowing agent comprising 1,1,1,3,3-pentafluoropropane and a hydrocarbonwherein the 1,1,1,3,3-pentafluoropropane is preblended with thehydrocarbon prior to being added to the mixture.
 5. A method forproducing polyurethane and polyisocyanurate foams comprising reactingand foaming a mixture of ingredients that react to form the polyurethaneand polyisocyanurate foams in the presence of a volatile blowing agentcomprising 1,1,1,3,3-pentafluoropropane and a hydrocarbon wherein the1,1,1,3,3-pentafluoropropane is added to the mixture prior to theaddition of the hydrocarbon.
 6. A closed cell foam composition preparedby foaming a polyisocyanate or polyisocyanurate in the presence of ablowing agent comprising an azeotrope-like composition consistingessentially of 1,1,1,3,3-pentafluoropropane, water and at least onehydrocarbon selected from the group consisting of n-pentane, isopentane,cyclopentane and hexane, which compositions have a boiling point of10±4° C. at 760 mm Hg.
 7. The closed cell foam composition of claim 6wherein the azeotrope-like composition consists essentially of fromabout 65 to about 98 weight percent 1,1,1,3,3-pentafluoropropane, fromabout 1 to about 34 weight percent water and from about 1 to about 34weight percent of at least one hydrocarbon selected from the groupconsisting of n-pentane, isopentane, cyclopentane and hexane.
 8. Theclosed cell foam composition of claim 6 wherein the azeotrope-likecomposition consists essentially of from about 75 to about 98 weightpercent 1,1,1,3,3-pentafluoropropane, from about 2 to about 24 weightpercent water and from about 1 to about 24 weight percent of at leastone hydrocarbon selected from the group consisting of n-pentane,isopentane, cyclopentane and hexane.
 9. A closed cell foam containing acell gas comprising a blowing agent comprising an azeotrope-likecomposition consisting essentially of 1,1,1,3,3-pentafluoropropane,water and at least one hydrocarbon selected from the group consisting ofn-pentane, isopentane, cyclopentane and hexane, which compositions havea boiling point of 10±4° C. at 760 mm Hg.
 10. The closed cell foam ofclaim 9 wherein the azeotrope-like composition consists essentially offrom about 65 to about 98 weight percent 1,1,1,3,3-pentafluoropropane,from about 1 to about 34 weight percent water and from about 1 to about34 weight percent of at least one hydrocarbon selected from the groupconsisting of n-pentane, isopentane, cyclopentane and hexane.
 11. Theclosed cell foam containing a cell gas comprising a blowing of claim 9wherein the azeotrope-like composition consists essentially of fromabout 75 to about 98 weight percent 1,1,1,3,3-pentafluoropropane, fromabout 2 to about 24 weight percent water and from about 1 to about 24weight percent of at least one hydrocarbon selected from the groupconsisting of n-pentane, isopentane, cyclopentane and hexane.